Heart and Stroke Encyclopedia

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An implantable cardioverter defibrillator, or ICD, also called an automated internal defibrillator, is a device similar to a pacemaker that is implanted to detect and treat overly rapid abnormal heartbeats known as arrhythmias. When the ICD detects a dangerous arrhythmia, it delivers electrical shocks to restore a normal heartbeat.

Impaired fasting glucose is a form of prediabetes. It means that while fasting for eight hours, a person's blood sugar level is 100 to 125 mg/dL. People with impaired fasting glucose are at increased risk for developing type 2 diabetes, heart disease and stroke.

Impaired glucose tolerance is when the body is unable to break down, or metabolize, sugar adequately. The body uses a type of sugar called glucose for energy. People with impaired glucose tolerance, also called abnormal glucose tolerance, are considered prediabetics. They are at increased risk for developing type 2 diabetes, which is an important risk factor for heart disease and stroke.

An implantable cardioverter defibrillator, or ICD, is a device similar to a pacemaker that is implanted to detect and treat overly rapid abnormal heartbeats known as arrhythmias. When the ICD detects a dangerous arrhythmia, it delivers electrical shocks to restore a normal heartbeat.

Infant cardiopulmonary resuscitation is an emergency lifesaving procedure performed on a child under the age of 12 months who is not breathing. CPR procedures for infants are similar to CPR for adults but there are several important differences.

Endocarditis refers to inflammation of the heart lining or valves, usually caused by a bacterial infection. Risk for developing endocarditis includes those having had placement of a prosthetic heart valve, previous endocarditis, previous heart valve surgery, abnormal heart valves or certain congenital heart defects. Common symptoms include fever and other flu-like symptoms.

Insulin resistance is when a patient's body can't use insulin efficiently. The pancreas responds by releasing more insulin to try controlling blood sugar levels. Over time, the cells in the pancreas that produce insulin break down and even go away. That causes blood sugar levels to rise and diabetes to develop. Insulin resistance may be linked to obesity, hypertension and high levels of fat in the blood.

Intermittent claudication is poor circulation in leg arteries due to buildup of plaque. It is marked by pain, cramping or fatigue in the legs and buttocks during activity that diminishes or goes away when standing still. It is a common, early symptom of peripheral artery disease. Intermittent claudication may occur in both legs, and the symptoms often get worse over time. Smokers are especially at risk.

An intraaortic balloon pump is a device implanted to assist an ailing left ventricle to pump blood through the heart. An intraaortic balloon pump increases cardiac output and relieves pulmonary congestion.

An invasive procedure is when a healthcare provider uses a needle, tube, scope or other device that goes inside a patient’s body – thus, “invading” it. Examples of an invasive procedure range from a needle prick for a blood test to major surgeries.

Ischemic heart disease is a heart problem caused by heart arteries that are narrowed. When there are blockages in arteries, they become narrowed, which means less blood and oxygen reaches the heart muscle. When more oxygen is needed, such as while exercising, the heart cannot meet the demands. The lack of oxygen caused by ischemic heart disease can product chest pain, discomfort known as angina pectoris or even a heart attack.

Ischemic stroke occurs when a blood clot or other particle blocks an artery in the brain or an artery leading to the brain. This causes brain cells to die or be injured. Cerebral thrombosis and cerebral embolism are ischemic strokes.